Hydraulic resistance device



Se t; 16, 1930. E. w. ACKERMAN ETAL 1,775,840

HYDRAULIC RESISTANCE DEVICE Filed Nov. 23, 1928 lllll Q Q E k v6. A M

INVENTORS BY W ATTORNEY.

1*- :opening.

' Patented Sept. 16, 1930 UNITED STATES PATENT OFFICE ERNEST W. ACKERMANAND GRIFFITH O. NICHOLSON, OF MONROE, MICHIGAN, AS-

SIGNORS TO HYDRO-CHECK CORPORATION, OF MONROE, MICHIGAN, A CORPORATIONOF MICHIGAN HYDRAULIC RESISTANCE DEVICE Application filed November 28,13:28. Serial No. 321,303.

"This invention relates to resistance devices for retarding travelbetween two relatively movable connected members.

This invention has utility when incorpovl5 rated .in auxiliaryconnections between the axle and chassis of motor vehicles for reboundtake up.

Referring to the drawings: V

,;Fig; l is a View in vertical section-through 7 1 thecasing,,otanembodiment of the device in a ,hydraulic pneumatic type of reboundresistance for motor vehicle application; and Fig.2 is a;section on theline 22, Fig. 1,

looking int-he direction of the arrow.

1-5 jTlllfOugh openings lin ears'2' bolts may connect casing 3 :forfixed mounting with thechassis of ;a motor vehicle as shown in Patent,1,6l0,6d l, Dec. 14, 1926. Through adateral opening inthis casing 3,there ex- 20 tends rock shaft 4 with -which is fixedly mounted ;arm;5:tor connection to the axle of the vehicle, thereby, in the relativeshitting Qfithe chassis -to the axle, to effect movementgof cam arm'6asacting on piston head 25 7 against the thrust of helical compressionspring 8, seated on cylinderhead 9 integral with the casing 3, andhaving clearance 10 as to ,imperi orate bottom 11 of this casing 3,Remote from this closed bottom 11, the

- casingfihasopenytop l2 with seat for gasket 13 ag inst which-isfixedly anchored closure or top 1,4 in providing closed upper airchamber 15 for such compressible medium.

The lower portion of this casing 3 con- 35 tainsjliquid 16 astheincompressible medium coacting in the operation of this devicehereunder. This incompressible medium is de sir-ably maintained atalevelbelow the top of cylinder 17 as, an integral walLrising from thecylinder ;head 9. This level for the liquidas castor.oil,alcohol,glycerin, cylinder stock, or combination thereof, may be determinedbyfilling the casing3 up to the orif ce; asclosed by fillingplug 18. -The cylinder 17 near its lower portion has enlarged diameterregion 19 in which there is located lateral port 20. This port 2Q has'its capacity reduced by taperedv stem 21soth-a-t this port may .act asa seepage no Thisstem 21 has threaded enlargement 22 mounted in internalboss 23 of the casing 3, so that this stem may be longitudinallyadjusted to vary the eli'ective seepage capacity through the port 20. Assuch adjustment is determined, packing 24 may be disposed in this boss23 and plug 25 as a concealing means assembled thereover.

The cylinder head 9 is shown as having port 26 with which is threadassembled tower valve tubular housing 27, housing secondary helicalspring 28 coacting between shoulder 29 oi" the tubular housing andshoulder 30 or relief-valve sleeve 31 having reduced diameter portion 32in the region of port 33 as communicating with the interior of thecylinder 17. This reduced diameter portion 32 provides a pressure regionel'lective as pressure builds up in the cylinder 17 to force this reliefvalve sleeve 31 against the action of the spring 28 thus allowing, inaddition to the escape by the seepage port 20, flow through the port 33past depending sleeve portion 3dof seat member 35. This relief flow isthence through opening 36 centrally of the shoulder 30 and throughopening 37 into the clearance 10.

This seat member has thereover seat 38 for ball check valve 39 normallyclosed as pressure is built up in the cylinder 17. However, as there isaction of the arm 5 cansing the cam 6 to move away from piston head 7,the spring 3 tends to thrust this piston out of the cylinder, therebyreducing the pressure in the cylinder and lifting the ball 39 for freeinflow ot the incompressible medium 16 into the cylinder 17. The quickaction in this operation tends to throw the ball 39 upwardly and in suchmovement it strikes spring 40 on pin 41 as anchoring sleeve 42. Thispull thus holds the seat 38 assembled in the tower valve unitarystructure and holds the hall 39 from snapping outward as well as quietsany hammering ac- .tion of this ball in its upward throw or jum v Tliepiston as provided with the head 7 has downwardly depending primary ormajor skirt portion 43 and secondary or minor skirt portion tl of lessdiameter, concentric or the piston, and in closer proximity to thepiston head 7 than the major skirt portion 43. This inajorskirt portion43 houses the helical spring 8 to an extent and serves to guide thepiston in the major region of the cylinder 11 This minor skirt portion4.4 is separated from-the major skirt'portioni43' by shoulder 45providing a seat for this compression heli cal spring 8.

In the carrying out of the invention herein to permit this devicetohavecompressible' fluid medium range before the greater resistance ofthe incompressible fluidya region Within the piston for compressiblemedium and the replenishmentof such is provided;

To this end, from the shoulder 45 there ex tends" port 46 having itsterminus 1n the shoulder 450i such dimension that the spring S-may notbe elfective fully to close this port; From this larger capacity'reg'ionof the port as adjacent the shoulder 45, this port 4611p 'WardlyI extends to minor capacity; upward terminal port 47. I

I In practice. hereunder, the upward thrust c c of thefpiston thusreducing the pressure Withinthe skirt of, thepiston, is eifective in"the port portion 46 asof considerable capacity,thuscreating a quickpull for the 'minor'capacity' port region 4'T,readily clear- :ging-such'of any incompressible medium t cumulation so thatthe compressible mediummayfiow into the skirted region'of the p1ston during piston rise. Atonce on piston "compression, the reserve floWjthrough-this 1 multiplediameter port 46', 47, under the pressure exerted by the eam 6, tends tomaintain,

the minor capacity port portion LT-clear of cloggingaction. vAs thepiston depressilnr appro aches" the surface of the incompressiblemedium'lfi, there is trapped upward from the shoulder 45 and intheregion ofthe secoI Clar skirt 44, the residue'of this comoressiblemedium Which serves as-a cushion" in minor rocking movements'of the armhas to the casing? f In practice, in motor'vehicle operations iwiththe'device hereunder, the locationof the shoulder 45 as to the-head 7may be such to maintain a desired capacity for this minor or secondaryskirt regionjand "thus definitely determine the effectiveness of thecompressible medium coaction before thehydraulic medium takes hold forthe retarding control in-the operation of thedevice-hei-e- "under. Theoperation of arm Sin'depressing the piston head 7 is'p ositive and' thecam 6 has not only key. assembly position with the shaft4, but hassupplemental SShSClBW 48 as a lostm'otion take up additional key.

. lVhatis claimed and itisdesiredtosecure by Letters Patent is: r

1. hydraulioresistance interposing device comprisingacasing fora'liquid'and providing a cylinder to extend above thenormalliquid levelin the casing, and. a pistonfin the cylinder having ahead and remotefrom the head a primary portion and acent the heada secondary dependingskirtportion and anormally open port havingcommunication from above theliquid coacting in piston operationfor maintaining a trappedcompressibl'emediumin thesecondarv skirt portion.

"2. A hydraulic resistance interposing de-' I vice comprising a casingfor a'liquid and providing a cylinder to extend above the normal, liquidlevel in thecasing, a piston i'n'the yne: derhavinglahead, aprimaryjskirt portiohide, I

pending remote from the haayascbaaar depending skirt portionytowardthehead from. the primary portion, and a normally open port throughthe'head for maintaining a ary skirts portion; 1

trapped compressible medium in the second-j 3; A. "hydraulic resistanceinterposing dee V106 compris ng a casing'fo'r a hquidand providing acylinder to extend above the normal liquid level in the casing,a-pist'on i'n the cylinder having a head, depending skirt means';and anormally open p'ort'throu'gh the head ter minating spaced from the'inner side of the n I head for-maintaining a trapped compressible mediumvvithinthe skirt means in the region: ofsaldhead-j hydraulicresistanceinterposingidevice comprising aca-sing'for a liquid: and providing acylinderto extend above the normal liquid level in thecasing, a pistonin the cyl inder having a' head 'deipending skirt means; i I and'amultipletransverse dimension normally: I c V open port throughtheh'ead'intothe' region of said skirt means" for mai'ntaining a trappedcompressible medium vv-ithin;theskirt means in the region ofsaid head 7j "5; AIhydraulioresistanceinterposing def i i vice comprising,a casing'for al quidand'proa vidinga cylinderto extend above the normalliquid level the casing, a helical springin the cylinder, c and apistonin the cylinder urged upward by saidsprin'g; saidpiston havingadepending skirt about 'the'spring and ash'oulder Within theskirt'engaging the spring, *and 'normally open portfmeans. for Imaintaining a trapped compressiblemedium-:

below the piston.

6, A hydraulic resistance interposing device comprisingacasing'foraliquid and providing a cylinder to extend above the normal upper portregion onpiston rise. V

' 7. -A hydraulic resistance interposing as vice comprising a casingfora liquid and proa 1 v dmg a cylinder to extend above thenormal liquidlevel in the casing, a helical spring in c the cylinder, and a piston inthe cylinder urge'd upward 'by said spring, said piston having'adepending skirtaboutthespring and a shoulder Within the skirt engagingthe has spring, andnormally open port means from the shoulder throughthe piston head.

8. A hydraulic resistance interposing device comprising a casing for aliquid and providing a cylinder to extend above the normal liquid levelin the casing, a helical spring in the cylinder, and a piston in thecylinder urged upward by said spring, said piston having a dependingskirt about the spring and a shoulder Within the skirt engaging thespring, and port means from the shoulder and upward through the pistonhead, said port means having a minor capacity terminus and at theshoulder a larger capacity section. V

In Witness whereof We affix our signatures.

ERNEST W. ACKERMAN. GRIFFITH C. NICHOLSON.

